Such an injector is generally known in the art and is used for, for example, introducing identification means such as transponders into living beings such as pigs. Such transponders can be accommodated in a cartridge, which cartridge is fitted in an injector, and the transponders are moved by means of a push rod out of the cartridge into the hollow needle. With said hollow needle an incision is first made in the skin and the underlying tissue of the animal is exposed, and the transponder is then moved into its end position with the aid of the push rod. The needle is then withdrawn.
Although various proposals have been made for limiting as much as possible the introduction of impurities into the incision in the living being, such as making a U-shaped incision in the skin, the risk of infection still remains. The risk associated with infection is that the transponder will be expelled from the body of the animal through the body's defence mechanisms.
It was therefore proposed in the art that disinfectants should be used during the insertion of the transponder. Such disinfectants can be moved together with the transponder into the living being in question. One possibility is to confine the transponder in a cartridge with an ointment-like material having disinfectant properties. When the transponder is ejected from the cartridge, said ointment will also be conveyed. It was, however, found in experiments that only a limited part of the ointment present in the space of the transponder goes into the skin at the incision. In experiments less than a few per cent was found in the wound itself. The major part of the ointment remains behind in the injector. It was also found that a considerable variation existed in the quantity of disinfectant introduced into the wound. The certainty of the transponders remaining in the body is therefore reduced, and subsequent checking is necessary. Efforts toward the general use of transponders in livestock are thus impeded.
This means that the injector must be made in such a way that it is always ensured that an adequate quantity of disinfectant is introduced into the wound. On the other hand, too much disinfectant must not be introduced into the wound, because this can slow down the encapsulation of the transponder inside the animal, or can have other negative effects.